Capturing and Recycling Excess Nutrients from Farmland

Excess nutrient runoff from agricultural fields has been a major issue in the Midwestern U.S. for decades. This runoff results in downstream issues such as reduced water quality, higher treatment burden for water treatment plants, and eutrophic conditions like in the Gulf of Mexico’s dead zone. Agricultural best management practices such as no till farming and timing of fertilizer applications have significantly reduced the nutrient load, but are a long way from meeting appropriate environmental standards.

Designer Biochar to Capture and Recycle Phosphorous from Tile Drainage Systems

To combat excess phosphorus runoff problem, Wei Zheng and BK Sharma of ISTC along with other colleagues from the University of Illinois at Urbana-Champaign, the Metropolitan Water Reclamation District of Greater Chicago, Water Warriors, Fulton County Farm Bureau, and Illinois Farm Bureau believe that they can engineer a solution to keep phosphorus within the agricultural system and out of the aquatic environment. They have proposed to combine a woodchip bioreactor with designer biochar to capture phosphorus within the biochar. Biochar is a charcoal-like product produced by the pyrolysis of biomass and is composed largely of carbon.

The biochar can be removed from the bioreactor system periodically and spread over the field as a form of slow release phosphorus fertilizer. The bioreactor/biochar-channel system will be tied into the tile drainage system to remove excess nutrients before the water is released to a nearby stream. The team also believes that the bioreactor system will reduce fertilizer expenses with the capture and reuse of excess phosphorus on the designer biochar.

This project is funded by the Illinois Nutrient Research & Education Council. Results are expected in spring 2023.

Development of a Novel Bioreactor and Biochar-Sorption-Channel (B2) Treatment System to Capture and Recover Nutrients from Tile Drainage

Principal investigator Wei Zheng and colleagues from the University of Illinois and Metropolitan Water Reclamation District of Chicago received further funding from the U.S. Environmental Protection Agency expand the NREC project. This grant is to develop and scale up B2 system to remove both nitrogen and phosphorus. If successful, this technique will provide a cost-effective way to recycle nutrients back to farm fields.

The U.S. Environmental Protection Agency is funding this three-year $1 million project. Read more about it on ISTC’s blog or in the U.S. EPA’s press release.

woodchip bioreactor system

Proposed nutrient removal system.

Video produced by Illinois Farm Bureau at Fulton County Field Day on July 16, 2019